1. Field of the Invention
This invention relates to an improvement of a camera in respect of a reduction in size of the camera.
2. Description of Related Art
There has been known a camera in which a wall part surrounding a spool chamber is formed in a camera body and a roller spring attached to the wall part is arranged to press a film against a spool, as proposed in Japanese Laid-Open Patent Application No. HEI 4-349443, etc.
FIG. 5 is a transverse sectional view schematically showing a spool chamber of the conventional camera of the above-stated kind. The illustration includes a camera body 1 and a spool chamber wall 1a formed in the camera body 1. A groove part 1b is formed in the spool chamber wall 1a and arranged to hold a camera-body-side roller spring 8 which is press-fitted into the groove part 1b.
A spool chamber 2 is arranged to accommodate a photographing film 9 there in an encircling manner. A film take-up spool 3 which is disposed within the spool chamber 2 is arranged to be driven to rotate during film winding and to idly rotate during film rewinding by a film transport means (not shown).
A back cover 5 is arranged to shield from light an aperture part 1c formed in the camera body 1 and the spool chamber 2. A back-cover-side roller spring 4 which is mounted on the back cover 5, is arranged to press the photographing film 9 against the spool 3.
A fixed tube 6 constitutes an outermost peripheral part of a photo-taking lens barrel. A photo-taking lens barrel unit 7 is stowed in the fixed tube 6. The camera-body-side roller spring 8 is arranged to press the photographing film 9 against the spool 3. At the time of assembling of the camera, the camera-body-side roller spring 8 is made to be inserted into the spool chamber 2 from the direction of the back cover 5 and to be press-fitted into the groove part 1b formed in the camera body 1.
An inner rail 1d, which is molded integrally with the camera body 1 is arranged to regulate the position of the photographing film 9 on the front side thereof in the direction of an optical axis within a film transport path formed between the back cover 5 and the camera body 1.
Next, movement of the photographing film 9 in the camera configured as described above is discussed. The photographing film 9 which has been sent out from a film cartridge by the film transport means (not shown) passes through the film transport path and then enters the spool chamber 2. With the photographing film 9 further sent out, the fore end of the photographing film 9 comes to abut on the back-cover-side roller spring 4 to be pressed against the spool 3. When the spool 3 is caused to rotate, in this state, in the direction of film winding (clockwise as viewed in FIG. 5 ), the photographing film 9 begins to be wound around the spool 3 due to friction brought about by the pressing force of the back-cover-side roller spring 4.
When the photographing film 9 is further sent out, the photographing film 9 is guided between the wall surface of the spool chamber 2 and the camera-body-side roller spring 8. Then, as shown in FIG. 5 , the photographing film 9 is sandwiched between the camera-body-side roller spring 8 and the spool 3 to be taken up onto the spool 3. When the photographing film 9 has been wound on the spool 3 to the extent of a maximum number of photographing frames, the camera-body-side roller spring 8 is elastically deformed up to a position 8a shown in FIG. 5.
While the camera shown in FIG. 5 includes the camera-body-side roller spring 8, some cameras are provided with no camera-body-side roller spring, as shown in FIG. 6.
Referring to FIG. 6 , a rib 10 which protrudes into the spool chamber 2, is arranged to prevent the photographing film 9 from falling in between the spool 3 and the spool chamber wall surface on the side of the lens barrel, to prevent light from easily entering into the spool chamber 2 through the aperture part in the event of an excessive amount of exposure, and also to cause the photographing film 9 to have a better flatness at the aperture part.
In each of the cameras shown in FIGS. 5 and 6 a part of a camera body on the front side of the camera, i.e., the spool chamber wall 1a located on the side of the lens barrel, and a part of a photographing lens barrel, i.e., the fixed tube 6 are disposed side by side in the transverse direction of the camera. Such a side-by-side arrangement presents a problem in terms of a reduction in size of the camera, because of an increase in the transverse dimension of the camera.
Further, as shown in FIG. 5 , in a case where the camera body 1 is to be molded by pulling out a mold in the direction of the back cover 5 the groove 1b which is to be used for press-fitting the camera-body-side roller spring 8 can be formed only in a position where it laterally overlaps the spool chamber wall 1a. Therefore, the groove 1b also hinders the reduction in size of the camera in its transverse direction.
Further, as shown in FIG. 6 , in a case where the camera body 1 is to be molded by pulling out a mold in the direction of the back cover 5, it is extremely difficult to have the rib 10, which protrudes into the spool chamber 2, molded integrally with the camera body 1. The rib 10 therefore, has to be molded separately from the camera body 1. The two parts, i.e., the rib 10 and the camera body 1, then necessitate a process of joining them together at the time of assembling of the camera. This process causes an increase in cost of the camera.
In addition, in a case where the rib 10 shown in FIG. 6 is attempted to be molded integrally with the camera body 1 shown in FIG. 5, even if they can be molded integrally, it becomes extremely difficult to have the camera-body-side roller spring 8 embedded or incorporated into the camera body 1 as shown in FIG. 5. Besides, the work of embedding the camera-body-side roller spring 8 in the camera body 1 becomes more difficult accordingly as the camera-body-side roller spring 8 is arranged to be closer to the spool chamber wall 1a. At present, therefore, the rib 10 has to be molded separately from the camera body 1.